The way Dalvik works is this: It takes a bunch of Java bytecodes and converts them to Dalvik format so they run on Android. This is done automatically by an Eclipse plugin. You can take Java projects that were never meant to run on Android, and run them on Android. Eg, I use Apache Lucene (a big project) in one of my Android apps. The entire J2SE JDK is not available on Android, but all the important parts are. J2SE is old and Sun’s insistence on never breaking backward compatibility has created a lot of cruft (eg, Swing). Some Sun projects are just bad (eg, RMI). It is easy to write apps that run on both Android and desktop using the same codebase.
